Gems and Their Exploration: A Geological Perspective

This study provides a comprehensive analysis of gemstones, focusing on their geological formation, exploration, mining practices, and socioeconomic and ethical issues surrounding the industry. Gemstones, such as diamonds, rubies and sapphires, form through various geological processes, including igneous, metamorphic, hydrothermal, and sedimentary mechanisms. For example, diamonds crystallize deep within the mantle of the Earth and are transported to the surface through kimberlite pipes, while rubies and sapphires commonly occur as phenocrysts in metamorphic rocks, as observed in the Chanthaburi and Trat districts of Thailand (Gem Society, 2025).).Exploration methods have evolved from traditional mapping to advanced geophysical surveys, such as aeromagnetic and seismic profiling, which are effective in identifying kimberlite pipes and cratonic regions. Ground-penetrating radar is also used for detailed mapping of gem-bearing cavities (CSEG Recorder, 2023). Mining techniques vary by deposit type and include open pit, underground, and alluvial methods. Artisanal and small-scale mining dominate the colored gemstone sector, particularly in regions rich in emeralds, sapphires, and rubies. For example, alluvial mining is prevalent in Madagascar for sapphires, whereas open-pit and underground mining are used in South Africa for diamonds (Gem Society, 2025).Gemstone mining has complex socioeconomic impacts, generating employment and infrastructure, but also causes environmental degradation and social conflict. Sustainable mining practices and community participation are essential to mitigate negative effects and ensure local benefits (Kings Mines, 2024). Ethical concerns, especially regarding conflict diamonds, have prompted initiatives such as the Kimberley Process, although challenges remain (Kimberley Process, n.d.). The rise of lab-grown diamonds offers a more ethical and sustainable alternative, reflecting consumer demand for transparency and responsible sourcing (Vandrake Jewelers, n.d.). Visual aids, such as diagrams of the formation processes and mining techniques, are recommended to clarify these complex topics. The global gemstone market is projected to grow significantly, highlighting the importance of sustainable practices (Future Market Insights, 2025).